html {
    animation-name: html;
    animation-duration: 3s;
    animation-timing-function: ease-in-out;
    animation-fill-mode: forwards;
}

#main-content {
    color: white;
    background-color: black;
}

@keyframes html {
    0% {
        background-color: white;
    }
    100% {
        background-color: black;
    }
}